Static-reducing system



STATIC REDUCING SYSTEM Filed 001;. 20, 1921 Aece/ker 'WITNESiy: INVENTOR Jbseph. Slepian.

Patented Mar. 27, 1928 UNITED STATES PATENT OFFICE.

JOSEPH SLEPIAN, OF SWISSVALE, PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

' STATIC-REDUCING SYSTEM.

Application filed October 20, 1921. Serial No. 509,166.

My invention relates to protective systems and more especially to apparatus and circuit arrangements adapted to minimize the disturbing elifects of static impulses in wireless receiving systems.

An object otmy invention is to provide an improved receiving system embodying means whereby the disturbing effects of atmospheric electricity or static disturbances may be simply and efllciently eliminated.

It is found that many static disturbances in a wireless receiving system consist of a brief impulsive blow to the antenna system during which time energy is stored in the antenna, and this energy in'nnediately after wards manifests itself by an oscillation having the natural period and the damping of the antenna system. The distinction, therefore, between such disturbances and received signal impulses is that the energy is stored in the antenna only in the first impulse of short duration.

According to my invention, I provide means adapted for use in connection with well known types of receiving systems,

whereby the energy in the initial impulse of the static disturbance may be absorbed in an impedance device, thereby preventing the static impulse from storing energy in the antenna in the "form of natural oscillations and, as a result, producin substantially no effect upon the receiving system. In carrying out this feature of my invention, I select an absorbing impedance that will absorb but little energy of the signaling frequency al though eliectively damping the impulses due to static disturbances.

The desired, result may be accomplished by including in the receiving circuit a pair of high-i1npedance, inductive-reactance devices and shunting each device by a rectifier, the several rectifiers being oppositely dirented.

Other objects and applications of my invention. as well as details of construction, wlmreby my invention may be practiced, will be ap imrent in the following-descrip-- tion and claims when read, in connection with the accompanyingdrawing, wherein The single figure is a diagrammatic view of a wireless receiving system embodying my invention.

In the single figure an antenna 1 is con nected to a ground conductor 2 through a tuning coil 3 and a pair of serially connected high-impedance, inductive-reactance devices 4 and 5. The inductance-reactance device 4 is shunted by an asymmetrical conducting device or rectifier 6 while the inductive-reactance device 5 is shunted by a similar asym metrical conducting device or rectifier 7, the two rectifiers, however, being oppositely directed. The combined impedance of the devices 4 and 5is great enough if the shunts 6 and 7 were omitted. to render the antenna circuit aperiodic.

lVave responsive apparatus (not shown) may be operatively connected to the antenna circuit through conductors 8, 9 and a coupling coil 11, the latter member being operatively associated with the tuning coil 3. In operation, upon the receipt of signal lmpulses, the effect of successive positive half-cycles is to cause unidirectional currents to progressively build up in a circuit 12 which includes the reactance device 4. and the rectifier 6. The direction of the currents is as indicated by arrow or in the drawing. The final value of the currents is that of the peak value of the currents in the antenna circuit.

Similarly, the effect of the successive nega tive half-cycles is to cause similar unidirectional currents to traverse a circuit 13, the latter including the reactance device 5 and the rectifier 7. It will be noted, however, that the currents in this circuit are in a reverse direction to those in circuit 12, as indicated by arrow Z). Here again, the final .value of the currents is that of the peak tween zero and twice the normal unidirectional-current value.

Upon the receipt of the disturbing impulses, however, having potentials greater than the peak potentials of the received signal impulses, positive halt cycles are blocked by the rectifier 6, and, similarly, negative half cycles are blocked by the rectifier 7,With the result: that the totallenergy of the dis turbing impulse is absorbed in inductance coils sand 5. The energy Which is thus absorbed in the inductance coils is dissipated in the resistance of the closed circuits 12 and 13.

In view of the foregoing description, it can be readily seen'that, for signaling impulses, the rectifiers serve as low impedance paths aroundthe several impedance devices but that, for disturbing impulses having steep waved'ronts, and potentials above the peak of the signal current potentials as are found in static impulses, the rectifiers serve ashiglnimpedance paths tending to admit otthe inductive devices 4 and 5 rapidly damping out the disturbing impulses.

While I have (ilescribeijl certain characteris-' tic forms of my invention indetail, and While I have: pointed out certain of the most obvious principles and purposes thereof, I do not'intend the language employed in the following claims to be limited to the precise features described, but I intend that the claims shall be construed to cover all combinations which are fairly included in the language thereof, when made in connection With the prior art, regardless oi the details and function mentioned in the description or illustrated in the drawing.

I claim as my invention: 1. In flll-elGClll'lCtll system, a circuit carrying oscillatory currents, a high-impedance device included in said circuit and means for renderingsaid impedance device substantially non-effective for said currents, said means being el'li'ecti ve for sustained signaling waves independent of the amplitude thereof andsubstantially ineii'ective l or cur-- rent impu lses of brief duration.

2. In awirelesa receiving system, an an tenna circuit for receiving signal impulses,

for current corresponding to the natural frequency of said resonance, said means being independent of the amplitude of said current and leaving said impedance device effective for-disturbing impulsesof' brief durat-ion, said means comprising a pair of oppositely asymmetrical conducting paths eachin shunt to a= different portion of said impedance element.

4. In a wireless receiving system, a receiving"conductor,'a pair of high-impedance devices included in circuit therewith, the impedance of' said' devices being such as to dampv out static as well as signalimpulses, and means shunting each de-vice'for, rendering said devices ineffective for currents having predetermined characteristics, said means being independent of the amplitude.

ot saidcurrents and substantially ineffective for steep Wavefront surges impressed upon said conducton 5. Iniawireless receiving system, a receiving conductor, apair oifliighdmpedance, inductiveereactance devices seriallyincludedin circuittherewith, the impedance otsaid devices being such as to render said'coiulnctor non-oscillatory, and an asymmetrically conducting path shunted, around each device, said. paths being oppositely directed, whereby. saidimpedance devices may berendered ineffective, for received signalimpulses, said paths being ineffective, respectively, for steep Wave-front surgesot opposite poten* tial, theetfectiveness of said, paths being-independent of the current strength.

6-. Ina Wirelessreceiving system, a'receiving conductoiy, means included] in circuit therewith for damping outstatic impulses and alow-impedance path around said tirstmentioned means,'said path including means coo eratiii with Stlld l'll'Shellitll'lBCl111611115 to determine a critical potential dependent uponthe. magnitude of the-steady received signal. impulses and for rendering the path ineffective above saidcriticalpotential.

7. In=a wireless receiving system, a receiv ing conductor, an inductive impedancedevice serially included in circuit therewith forlrendering said conductor non-oscillatory and -a pair oflow impedancev paths arouud said-x.lirstementioned inductive impedance, saidpatlis each includingmeans cooperating with said inductive. impedance, to determine a criticalpotential dependentupon the mag nitude -otthe steady received signal impulses and for rendering the path ineffective above said critical potential and said means be ing oppositely connected in the respective path's- 8. In a wireless receiving system, a receiv mg conductor carrying currents having positive and negative half cycles, a pair of" indiictive-reactance devices serially'included 1n cn-cuit'therewith, a path'shunting each device, an asymmetric resistor in each'path,

said resistors being oppositely connected and each constituting approximately all the re sistance in the respective paths. 1

9. In combination with a receiving circuit, means for preventing response therein to impulsive energy while permitting response to signaling energy, said means including a network presenting large and ap: proximately constant impedance to impulsive energy and low impedance to signaling 11. The combination with an alternating current circuit to be protected from currents having an abnormally steep wavefront, of protective means including a pair of seriesconnected inductors in said circuitand a shunt path for each inductor, each path including a devicecooperating with the respective inductors for causing a circulating unidirectional component of current having a value proportional. to the average maximum value of the alternating current in the alternatirig-current circuit, said circulating unidirectional currents in the respec-' tive inductors being in opposite directions, the current-carrying power of said devices being sufficient for the maximum expected c u rrents.

12. The combination with an alternatingcurrent circuit subject to current changes having a relatively small value per cycle and also subjected to current changes having a relatively large value per cycle, of protective means including a pair of series-connected inductors in said circuit and means connected in shunt to the respective inductors for effecti ng the establishment of circulating unidirectional components of current having a value within the limits of substantially said small value, said means having a current-carrying capacity sufiicient for said current changes of relatively large value and said circulating unidirectional currents in the re spective inductors being in opposite directions.

13. In an electrical system, a circuit adapted to be energized from a desired source of alternating currents and also from an undesired source of currents having relatively steep wave-fronts, impedance iliary means being capable of carrying currents of any strength up to a magnitude that would injure the apparatus.

14. The combination with an alternatingcurrent circuit to be protected from currents having an abnormally steep wavefront, of protective means inc uding a pair of multiple paths serially connected in said circuit, each of said multiple paths comprising a main path carrying currents substantially constant during the absence of said currents liavin abnormally steep Wavefront and an auxifiary path carrying currents varying during said absence between the limits of substantially zero and substantially twice the currents in said main path, the currents in the main paths of said pair of multiple paths being substantially equal and opposite in direction, and means for maintaining the stated current-flows in the several paths, said auxiliary paths having a current carrying capacity suflicient for the maximum currents expected in said circuit to be protected.

15. The combination with an alternatingcurrent circuit to be protected from currents having an abnormally steep wave-front, of protective means including a pair of seriallyconnected inductors connected in series with said circuit and a pair of asymmetrically conductive circuits, capable of carrying currents correspondin to the maximum expected amplitude of sand abnormally steep Wavefronts, connected in opposite directions in shunt, respectively, to said inductors.

16. In a protection device, an inductor, and a pair of asymmetrical resistance devices, one of said asymmetrical devices being connected in shunt to said inductor, and the other affording a passage for current through said inductor, whereby, when alternating current is impressed upon the protection device, the average current through said shunt will approximate the maximum current through said inductor, the conductivity of said passage being independent of the current strength.

17. In a protection device, a pair of inductors connected in series and a pair of asymmetrically conducting devices, one in shunt to each inductor, the conductive direction of said devices being away from the point where said inductors are connected to each other.

18. In a disturbanceeliminating device, an inductance divided into two parts, two 

